Instantiate specialized classes nested in templates

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/AST/ClassExtensions.cs

@@ -233,6 +233,20 @@ namespace CppSharp.AST
             return @interface;
         }
 
+        public static ClassTemplateSpecialization GetParentSpecialization(this Class @class)
+        {
+            Class currentClass = @class;
+            do
+            {
+                if (currentClass is ClassTemplateSpecialization specialization)
+                {
+                    return specialization;
+                }
+                currentClass = currentClass.Namespace as Class;
+            } while (currentClass != null);
+            return null;
+        }
+
         public static bool HasDependentValueFieldInLayout(this Class @class)
         {
             if (@class.Fields.Any(f => IsValueDependent(f.Type)))

src/CppParser/Parser.cpp

@@ -42,6 +42,7 @@
 #include <clang/Parse/ParseAST.h>
 #include <clang/Sema/Sema.h>
 #include <clang/Sema/SemaConsumer.h>
+#include <clang/Sema/Template.h>
 #include <clang/Frontend/Utils.h>
 #include <clang/Driver/Driver.h>
 #include <clang/Driver/ToolChain.h>
@@ -3053,8 +3054,7 @@ void Parser::CompleteIfSpecializationType(const clang::QualType& QualType)
         RD = const_cast<CXXRecordDecl*>(Type->getPointeeCXXRecordDecl());
     ClassTemplateSpecializationDecl* CTS;
     if (!RD ||
-        !(CTS = llvm::dyn_cast<ClassTemplateSpecializationDecl>(RD)) ||
-        CTS->isCompleteDefinition())
+        !(CTS = llvm::dyn_cast<ClassTemplateSpecializationDecl>(RD)))
         return;
 
     auto existingClient = c->getSema().getDiagnostics().getClient();
@@ -3065,8 +3065,7 @@ void Parser::CompleteIfSpecializationType(const clang::QualType& QualType)
     Scope Scope(nullptr, Scope::ScopeFlags::ClassScope, c->getSema().getDiagnostics());
     c->getSema().TUScope = &Scope;
 
-    c->getSema().InstantiateClassTemplateSpecialization(CTS->getBeginLoc(),
-        CTS, TSK_ImplicitInstantiation, false);
+    InstantiateSpecialization(CTS);
 
     c->getSema().getDiagnostics().setClient(existingClient, false);
     c->getSema().TUScope = nullptr;
@@ -3082,6 +3081,32 @@ void Parser::CompleteIfSpecializationType(const clang::QualType& QualType)
     }
 }
 
+void Parser::InstantiateSpecialization(clang::ClassTemplateSpecializationDecl* CTS)
+{
+    using namespace clang;
+
+    if (!CTS->isCompleteDefinition())
+    {
+        c->getSema().InstantiateClassTemplateSpecialization(CTS->getBeginLoc(),
+            CTS, TSK_ImplicitInstantiation, false);
+    }
+
+    for (auto Decl : CTS->decls())
+    {
+        if (Decl->getKind() == Decl::Kind::CXXRecord)
+        {
+            CXXRecordDecl* Nested = cast<CXXRecordDecl>(Decl);
+            CXXRecordDecl* Template = Nested->getInstantiatedFromMemberClass();
+            if (Template && !Nested->isCompleteDefinition() && !Nested->hasDefinition())
+            {
+                c->getSema().InstantiateClass(Nested->getBeginLoc(), Nested, Template,
+                    MultiLevelTemplateArgumentList(CTS->getTemplateArgs()),
+                    TSK_ImplicitInstantiation, false);
+            }
+        }
+    }
+}
+
 Parameter* Parser::WalkParameter(const clang::ParmVarDecl* PVD,
     const clang::SourceLocation& ParamStartLoc)
 {

src/CppParser/Parser.h

@@ -137,6 +137,7 @@ private:
     std::string GetTypeName(const clang::Type* Type);
     bool CanCheckCodeGenInfo(clang::Sema & S, const clang::Type * Ty);
     void CompleteIfSpecializationType(const clang::QualType& QualType);
+    void InstantiateSpecialization(clang::ClassTemplateSpecializationDecl* CTS);
     Parameter* WalkParameter(const clang::ParmVarDecl* PVD,
         const clang::SourceLocation& ParamStartLoc);
     void SetBody(const clang::FunctionDecl* FD, Function* F);

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -361,13 +361,11 @@ namespace CppSharp.Generators.CSharp
         private IEnumerable<Class> GetGeneratedClasses(
             Class dependentClass, IEnumerable<Class> specializedClasses)
         {
-            var specialization = specializedClasses.FirstOrDefault(s => s.IsGenerated) ??
-                specializedClasses.First();
-
             if (dependentClass.HasDependentValueFieldInLayout())
-                return specializedClasses;
+                return specializedClasses.KeepSingleAllPointersSpecialization();
 
-            return new[] { specialization };
+            return new[] { specializedClasses.FirstOrDefault(s => s.IsGenerated) ??
+                specializedClasses.First()};
         }
 
         public override void GenerateDeclarationCommon(Declaration decl)

src/Generator/Generators/CSharp/CSharpSourcesExtensions.cs

@@ -24,11 +24,9 @@ namespace CppSharp.Generators.CSharp
             var printedClass = @class.Visit(gen.TypePrinter);
             if (@class.IsDependent)
             {
-                IEnumerable<Class> specializations =
-                    @class.GetSpecializedClassesToGenerate().Where(s => s.IsGenerated);
-                if (@class.IsTemplate)
-                    specializations = specializations.KeepSingleAllPointersSpecialization();
-                foreach (var specialization in specializations)
+                foreach (var specialization in (from s in @class.GetSpecializedClassesToGenerate()
+                                                where s.IsGenerated
+                                                select s).KeepSingleAllPointersSpecialization())
                     gen.GenerateNativeConstructorByValue(specialization, printedClass);
             }
             else
@@ -40,10 +38,10 @@ namespace CppSharp.Generators.CSharp
         public static IEnumerable<Class> KeepSingleAllPointersSpecialization(
             this IEnumerable<Class> specializations)
         {
-            Func<TemplateArgument, bool> allPointers = (TemplateArgument a) =>
-                a.Type.Type?.Desugar().IsAddress() == true;
-            var groups = (from ClassTemplateSpecialization spec in specializations
-                          group spec by spec.Arguments.All(allPointers)
+            static bool allPointers(TemplateArgument a) => a.Type.Type?.Desugar().IsAddress() == true;
+            var groups = (from @class in specializations
+                          let spec = @class.GetParentSpecialization()
+                          group @class by spec.Arguments.All(allPointers)
                           into @group
                           select @group).ToList();
             foreach (var group in groups)

tests/CSharp/CSharpTemplates.cpp

@@ -109,8 +109,12 @@ void forceUseSpecializations(IndependentFields<int> _1, IndependentFields<bool>
                              VirtualTemplate<int> _6, VirtualTemplate<bool> _7,
                              HasDefaultTemplateArgument<int, int> _8, DerivedChangesTypeName<T1> _9,
                              TemplateWithIndexer<int> _10, TemplateWithIndexer<T1> _11,
-                             TemplateWithIndexer<T2*> _12, TemplateDerivedFromRegularDynamic<RegularDynamic> _13,
-                             IndependentFields<OnlySpecialisedInTypeArg<double> > _14, std::string s)
+                             TemplateWithIndexer<void*> _12, TemplateWithIndexer<UsedInTemplatedIndexer> _13,
+                             TemplateDerivedFromRegularDynamic<RegularDynamic> _14,
+                             IndependentFields<OnlySpecialisedInTypeArg<double>> _15,
+                             DependentPointerFields<float> _16, IndependentFields<const T1&> _17,
+                             TemplateWithIndexer<T2*> _18, IndependentFields<int(*)(int)> _19,
+                             TemplateWithIndexer<const char*> _20, std::string s)
 {
 }